DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2013 EXPERIMENTAL CAMPAIGN Review | Direct submission with log-in | Request submission without log-in
Print this page

Print this page
Title	13: Compare edge particle transport in ELMing H-mode and QH-mode with and without NRMF
Name:	Keith Burrell Burrell@fusion.gat.com	Affiliation:	General Atomics
Research Area:	Inductive Scenarios	Presentation time:	Not requested
Co-Author(s):	A. Garofalo	ITPA Joint Experiment :	No
Description:	The goal of this work is to measure the edge impurity particle transport in ELMing H-mode plasmas and contrast it with the edge particle transport in QH-mode both with and without n=3 nonresonant magnetic fields (NRMF). This will allow us to determine separately determine the net edge loss due to ELMs, EHO and EHO plus NRMF.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Create a QH-mode plasma with moderately low toroidal rotation which can be run both with and without NRMF. Inject fluorine into these plasmas using either LiF pellets or tetrafluoromethane gas so that we can study impurity transport with a non-recycling impurity. Use injection into QH-mode phases both with and without NRMF. Turn off NRMF and raise density until ELMs return; perform same measurements in ELMing H-mode. These measurements can be used as part of other QH-mode parameter scans to map out particle transport as a function of those parameters
Background:	QH-mode is an extremely attractive operating mode for future devices, since it exhibits H-mode confinement combined with steady-state operation without ELMs. Work in the 2009 and 2010 campaigns on D III-D has demonstrated QH-mode operation with zero-net NBI torque by replacing the NBI torque with torque from neoclassical toroidal viscosity produced using nonresonant n=3 magnetic fields. A key part of developing QH-mode with NRMF as an operating scenario for future devices is developing a predictive understanding of the edge particle transport. To develop a predictive understanding, we need to be able to measure the edge particle transport. Previous experiments in QH-mode without NRMF have used injection of pellets doped with LiF [K.H. Burrell et al, Phys. Plasmas 12, 056121 (2005)]. The essential features of fluorine is that it does not recycle, thus allowing direct measurement of the edge loss rate from the decrease of core density of fluorine. If we want a heavier, non recycling impurity, we could use chlorotrifluoromethane.
Resource Requirements:	Either lithium pellet injector or standard D III-D gas injector with fluorocarbon gases.
Diagnostic Requirements:	All standard profile and fluctation diagnostics, especially edge BES and ECE-I for EHO studies.CER tuned to F lines for impurity transport study
Analysis Requirements:
Other Requirements: